The National Marine Fisheries Service announced on Monday that it will grant the Navy another five-year permit to conduct training and testing exercises off the coasts of Southern California and the Hawaiian Islands.

Environmental groups say the decision will negatively impact marine mammals, because it allows for increased detonations of underwater explosives and in hours of sonar usage, which has been shown to interfere with how those animals navigate and search for food.

“There’s no way to understand today’s decision other than a white flag waved by a weak agency in the face of a strong one,” said Michael Jasny, director of the marine mammal protection project at the Natural Resources Defense Council. "Navy exercises are multiplying off California. Populations of whales are crashing here, and what is the administration doing? It’s whistling past the graveyard."

It's illegal to hunt, harass, capture, collect or kill marine mammals under the Marine Mammal Protection Act, but the government may receive exemptions in certain instances. Letters authorizing training and testing for the program state that no more than 155 marine mammal deaths will occur.

Officials said that the testing will be monitored throughout to see how mammals are being impacted.

A press release published on the National Marine Fisheries Service website lists mitigation measures it will require the Navy undertake to try to minimize harm to ocean animals.

From the site:

establishing marine mammal mitigation zones around each vessel using sonar;

using Navy observers to shut down sonar operations if marine mammals are seen within designated mitigation zones;

using mitigation zones to ensure that explosives are not detonated when animals are detected within a certain distance;

implementing a stranding response plan that includes a training shutdown provision in certain circumstances, and allows for the Navy to contribute in-kind services to NOAA’s Fisheries Service if the agency has to conduct a stranding response and investigation; and,

designating a “Humpback Whale Cautionary Area” to protect high concentrations of humpback whales around Hawaii during winter months.

An official from the National Marine Fisheries Service said she believes the actual number of injured or killed marine mammals will be fewer than for what the Navy is authorized.

“There have been cases in the past where sonar has been associated with marine mammal strandings, but we feel that the mitigation measures that we have put into place for this authorization will help prevent that,” said Michelle Magliocca, a fisheries biologist for the National Marine Fisheries Service.

Jasny said he is skeptical of the measures, because they are too limited and rely on human observation.

"The only thing the Navy is required to do is to shut down when they see animals in the water, but trying to spot a deep-diving whale or dolphin in the water at night in heavy seas - it's like shooting in the dark," Jasny said. "The administration itself has said that the most effective measure to reduce impacts on whales is to put important habitat off-limits."

Correction: An earlier version of this story stated the name of the Natural Resources Defense Council incorrectly. KPCC regrets the error.